1. The Field of the Invention
This invention relates to below ground vehicles used to transport equipment and personnel in below ground mining operations. More particularly, the present invention relates to methods for converting an above ground utility vehicle to a below ground utility vehicle and the resulting vehicles.
2. The Prior Art
Modern mining operations have a need for general purpose below ground vehicles. In the mining industry, vehicles are required to maneuver in low clearance mine roadways to transport personnel, maintenance equipment, fuel and lubricates, and other items from one location to another in the mining operation.
Below ground vehicles used in mining operations must have a maximum vertical height of eighty, and usually less than about sixty, inches and must be particularly suited to operation in the often hazardous and inhospitable mine environment. The vertical height of a below ground vehicle is generally measured from the underlying road or ground surface to the highest rigid structure on the vehicle.
While some mining vehicles must be able to carry payloads of anywhere in the range from hundreds to thousands of pounds reliably over rough road conditions, it is often necessary to transport only small items or a single mine worker. Above ground vehicles, which are intended for use on city streets and highways, are generally not appropriate for below ground mining use. Thus, it is widely recognized among those having skill in the art that above ground vehicles do not have application in the below ground mining industry.
The general recognition in the mining industry that even general purpose below ground vehicles must meet minimum safety standards and must include certain features has caused some manufacturers to produce specialized below ground vehicles. Generally, below ground mining vehicles must include features and structures which would be unsuitable for above ground vehicles for street and highway use. It is the usual case that specific below ground vehicles are custom built for the mining industry, e.g., vehicles are designed and built individually, or in quantities only in the tens, specifically for the mining industry. This is in contrast to the tens of thousands, or hundreds of thousands, of a particular chassis of a normal profile vehicle which will customarily be produced by a manufacturer.
Manufacturers of specialized below ground mining vehicles include: Eimco Mining Machinery International of Canada; A. L. Lee Corp. of Lester, W. Va.; and Getman Corporation of Bangor, Mich.
The market for such specifically designed and custom built below ground mining vehicles is very limited with some manufacturers producing only a few of each model each year. Thus, each below ground mining vehicle is generally built on an individual basis, or in very few numbers, to fill the need of a particular customer or class of customers.
It is widely acknowledged that producing such small numbers of specifically designed below ground mining vehicles is inherently inefficient. Thus, the cost of each vehicle is very high compared to vehicles which are mass produced and directed to a larger number of users.
Moreover, since so few below ground mining vehicles are built by each manufacturer, the design and fabrication of the vehicles requires that simple and readily available components, materials, and fabrication techniques be used. For example, in mass produced vehicles where tens of thousands are manufactured, such as above ground sport utility vehicles and small trucks, the frame, engine, drive train components, and body parts are all specifically designed and extensively tested to ensure that they work together properly and in a trouble free manner.
In contrast, prior art below ground mining vehicles are designed by each manufacturer and built in small numbers from the "ground up" with no other perspective in mind but to produce the vehicle for the intended specific end use. Thus, below ground mining vehicle manufacturers are left to obtain components such as engines, drive trains, and brake systems from sources where they are mass produced. The remaining components used in low profile vehicles such as frames and body parts, must be individually fabricated by the vehicle manufacturer.
As recognized in the arts devoted to design and production of vehicles for street and highway use, the compatibility of vehicle components is crucial to making a vehicle perform most efficiently. Ensuring that vehicle components are compatible requires a great deal of design, engineering, and testing effort before production of the vehicle begins. Such extensive design, engineering, and testing efforts are prohibitively expensive in view of the small numbers of below ground mining vehicles which are manufactured. Unfortunately, the use of "high quality" individual components does not ensure that the components will work well together.
Since the frames, bodies, and other components of prior art below ground mining vehicles must be designed and fabricated in small numbers, they are of simple construction and are fitted with components which are not ideally suited for use therewith. In the case of body parts, large flat pieces of sheet metal are generally attached to a simple geometric framework giving the completed below ground mining vehicle a "boxy" and "unfinished" appearance when compared to mass produced vehicles which are manufactured for street and highway use.
Moreover, the fact that each prior art below ground mining vehicle is individually designed and built causes most manufacturers to omit the design, fabrication and installation of many desirable features into their vehicles. Such omitted features may include performance enhancing features such as drive train, exhaust system, and suspension, braking, and fuel system improvements.
Also omitted from some prior art below ground mining vehicles are even basic amenities for the comfort and safety of the low profile vehicle operator such as cab environmental control, roll down windows, padded dashboard, windshield wipers, and windshield washers. In some cases, below ground mining vehicles do not provide the operator with any enclosed cab at all.
In view of the foregoing, it would be an advance in the art to provide a below ground mining vehicle which includes the desirable features present in above ground vehicles which are equipped for street and highway use while providing the below ground mining vehicle at a lower cost than prior art low profile vehicles. It would be a further advance in the art to provide a method of converting above ground vehicles for use as below ground mining vehicles. It would also be an advance in the art to provide a below ground vehicle conversion which allows below ground vehicles to be produced more efficiently than are prior art below ground vehicles which are designed and built in small numbers for specific end uses.